Adrenalectomy in Cats

Adrenalectomy in cats is a surgical procedure to remove either one or both of your cat's adrenal glands. The adrenal glands are a pair of endocrine glands located above each kidney. They produce hormones that perform several functions including:

• Blood pressure regulation/Control of salt concentration in conjunction with the kidney
• Production of sex hormones
• Reduction of inflammation
• Supporting immune system/aiding in healing
• Controlling carbohydrates /regulating blood sugar
• Metabolising fat in conjunction with pancreatic hormones 

The most common reason for removal of the adrenal gland is for the removal of tumors that would be life-threatening if they remain in place. Cushing’s disease is another condition causing chronic illness that may be treated with removal of the adrenal glands. Adrenalectomy is usually performed when other treatment options are not available, due to the risk of complications and requirement for ongoing treatment with medication after removal of adrenal glands. While the surgical procedure is high-risk, a cat that survives the procedure can live for several years postoperatively, whereas non-surgical intervention would have a poor outcome. An experienced veterinary surgeon is required to perform this complex procedure.

Depending on the type of tumor or condition requiring removal of the adrenal gland, your veterinarian may prescribe medication prior to surgery. For example, pheochromocytoma, an adrenal gland tumor that causes an excess of hormones that control heart rate and blood pressure may result in phenoxybenzamine being prescribed to control these issues. 

Also, trilostane may be prescribed to reduce cortisone levels and reduce the risk of blood clots may be prescribed prior to surgery by your vet.

Preoperative tests to determine your cat's overall health and condition may be performed to determine if your cat is a good candidate for this surgery. If your cat is on any medications or has any conditions this should be discussed.

Prior to surgery you will be required to fast your cat from food, water may be permitted; your veterinarian will provide you with specific information. 

Your cat will be given a sedative, followed by intravenous anesthesia administered by a catheter that will also be used to deliver IV fluids and medications during and post surgery. A breathing tube will be inserted to deliver oxygen and gaseous anesthesia. 

The site of incision will be clipped and cleaned with antiseptic prior to surgery. Your cat’s vital signs will be closely monitored during surgery to ensure vital functions are stable and any concerns with heart rate, oxygen levels or blood pressure changes will be addressed as required. Pain killers will be administered during surgery and post surgery to ensure your cat’s comfort.

Your veterinary surgeon will make an incision under the ribcage or on the side to access the adrenal glands and associated blood vessels. Each adrenal gland will be disconnected from the blood vessels and surrounding tissue and blood vessels tied off to prevent bleeding. After removal of the adrenal gland(s) the abdominal cavity will be rinsed with saline solution and closed with sutures.

Adrenalectomy may also be performed laparoscopically, if your veterinarian has the resources for this procedure. In this case, small incisions will be made in the abdomen near the navel to access the adrenal glands and a small camera inserted into the incisions used to guide the veterinary surgeon in the removal of the adrenal glands and cauterization of blood vessels. An ultrasound may be used prior to surgery to provide additional information to your veterinarian and guide the surgical procedure. The abdominal cavity may be expanded with gas to allow better visibility of the organs being surgically incised. 

Your cat will be hospitalized for a few days following surgery so that their recovery can be monitored and any medical intervention administered if required. Postoperative medication will be administered, including painkillers and any hormone replacement medications required.

The efficacy of removal of a tumor by adrenalectomy may be effective if the tumor has not metastasized and spread to other parts of your cat’s body. It is likely that additional treatment will be required and possibly ongoing treatment to address tumor growths.

If removal of only one adrenal gland was required, the remaining adrenal gland will compensate and additional hormone replacement may not be required. If both adrenal glands were removed, replacement hormone therapy will be required on an ongoing basis.

The surgical procedure is high-risk and several complications, such as blood clot to the lungs, resulting in morbidity and mortality, are possible. Adrenalectomy as a treatment for hyperaldosteronism tends to be associated with a better outcome than adrenalectomy for treatment of cancerous growths.

Laparoscopic adrenalectomy is associated with quicker recovery than traditional surgery as it is less invasive. Adrenalectomy in which both glands are removed will require ongoing hormone replacement therapy. 

A cat that survives the procedure and is released to a pet owner’s care has a good chance of recovery; most complications occur during or shortly after surgery.

If pheochromocytoma is present, medication to control blood pressure will be prescribed to increase your cat’s chance of recovery. Medication to control cortisol production (trilostane) may also help with your cat's survival chances by reducing the risk of blood clots.

Adrenalectomy is a complex surgical procedure with complex recovery issues and your cat will need to be closely monitored by both the pet owner and veterinarian postoperatively to ensure progress is made and issues are addressed. Medication prescribed to your cat during recovery may need to be adjusted and veterinarian follow-up will be required. Any concerns should be addressed with your veterinarian.

Due to the multiple considerations present and complications possible with adrenalectomy, costs can vary considerably. This surgical procedure can cost between $2,000 and $4,000 depending on the complexity of your cat's condition and your location.

Adrenalectomy is a high-risk surgery with several possible complications including hemorrhaging due to high vascularization, danger of blood clots to the lungs, risk of kidney failure, pancreatitis, or infection. Also, fluctuations in hormone levels related to immune system functions may further complicate recovery. This procedure has a high mortality rate, however adrenalectomy is performed due to urgent and severe conditions and not performing the surgery is usually associated with mortality. If your cat has normal blood pressure and blood chemistry findings prior to surgery, prognosis is more positive, and if metastasis of a tumor has not occurred and complications during and post surgery are avoided with careful veterinary care, long-term recovery can be achieved.

At present, the cause of cancerous growths in the adrenal glands is not well understood, it seems to be associated with stimulation from other hormone producing centers.

Diseases such as hyperaldosteronism/Cushing's disease are closely associated with feline diabetes and careful monitoring of a diabetic cat for signs of this condition will help with early intervention. In addition, management of diabetes including diet will reduce the manifestation of complications associated with diabetes and Cushings disease.